[Usefulness of cabergoline in patients with prolactinemia and resistant or intolerant to bromocriptine]

Dopaminergic agonists are the treatment of choice for prolactinomas with bromocriptine (BCE) being the primary agent used. There is a group of patients who are not responders to such therapy or have severe side effects (resistant or intolerant to BCE, respectively). We undertook this study to evaluate the response to the administration of cabergoline (CBG) in patients intolerant or resistant to BCE.

Twenty seven patients (25 females and 2 males) were recruited with prolactin-pituitary tumors, obtaining basal serum prolactin (PRL) samples and again each month up to 3 months. We recorded signs associated with hyperprolactinemia and secondary effects of CBG. The initial dose was 0.25 mg twice weekly during the first week, with an increase to 0.5 mg twice weekly from the second week until the conclusion of the study. Statistical analysis included Shapiro-Wilk, Kruskal-Wallis and ANOVA tests.

Twenty two patients had microadenomas and five had macroadenomas. In the intolerant group (n= 11), the initial PRL value (61.45 +/- 19.82) decreased by the third month to 4.94 +/- 1.79 (p<0.024). In the resistant group (n= 16), basal PRL values were 119.53 +/- 11.52. In 15 of these patients, the PRL value significantly decreased to 12.95 +/- 3.66 ng/ml (p<0.005) by the third month of treatment. In both groups the signs related to hyperprolactinemia significantly improved, with a low incidence of secondary effects due to CBG.

CBG is useful in most patients considered as intolerant or resistant to BCE.